GROWTH CONDITIONS
Day length: in general sesame is very sensitive to photoperiod. There are both long-
and short-day varieties, and even a few day-neutral varieties, such as “Venezuela
51”.
Growth period: 70–160 days, mainly depending on the variety - the average is
about 105 days. The pods and seed mature from the bottom of the plant upwards;
harvest should be timed to start when most of the lower pods have turned from green
to yellow. If harvest is delayed, the mature pods dehisce and some of the seed is lost
on the ground.
Temperature: the crop needs hot weather, and can tolerate very high temperatures,
about 27°C is optimum. The plant is frost sensitive. For germination soil
temperature should be about 20°C.
Rainfall: moderately drought resistant; it is extremely sensitive to excess soil water,
and so is normally only grown in low rainfall areas, around 350–1100 mm per year.
Some early varieties in retentive soils can produce a crop with stored soil moisture
alone. Heavy rainfall soon after sowing can lead to losses from soil capping and the
seeds being swept away or buried too deep.
Grows poorly in high rainfall, when Botrytis tends to develop, causing the heads to
drop off.
Pests: six of the insects which commonly cause some damage to sesame plants are:
- Til Leaf-Roller—specific to sesame. Larvae feed on the leaves and bore into the
stem and pods, killing plants at the seedling stage. - Tobacco Capsid—brownish yellow insects that suck the plant sap.
- Sesame Gall Fly—larvae feed on young flower buds, causing them to form galls
which fall off. - Aphids—transmit various virus diseases.
- Common Red Spider—a small 8-legged mite. Larvae cover the undersides of
leaves with a fine webbing and suck their sap; leaves become brittle and fall off. - Spheraylia sesami—larvae eat the flowers.
Diseases: humid conditions favour the spread of most of these: - Leaf Curl—a virus transmitted by the White Fly. The leaves curl downwards, and
- Phyllody—a virus transmitted by a jassid. Plants develop abnormal vegetative
growth, and the floral parts are transformed into green, leafy structures. The plants
become so heavy that they bend over. Resistant varieties are the best cure. - Leaf Spot—appears at flowering time, producing spots on the leaves, which fall
off early. Can be controlled with hot water treatment of seed. Destroy all infected
plants. - Fusarium Wilt—leaves turn yellow, and wilt, and the plant eventually dies. A
brown discolouration is seen when a transection is cut through the plant, which
spreads from the roots upwards. Controlled by using resistant varieties and clean
seed. - Root and Stem Rot—caused by fungi. A dark discolouration appears at the base
of the stem, which may break off at ground level, and the roots may become rotten.
Control with clean seed.
Altitude: 0–1500 m
stop it.
become thick, brittle and dark green. Weekly pesticide sprays may be needed to